It is well known in the art to provide a rear vision system for a vehicle such as a motor vehicle. Typically, the rear vision system includes a pair of outside or exterior side view mirrors, one on both driver and passenger sides of the vehicle, and an inside or interior rearview mirror in an occupant compartment of the vehicle.
Such a rear vision system may be power operated to allow a driver to adjust the side and interior rearview mirrors without physically attending them. These mirrors are typically adjustable both vertically (up/down or elevation) and horizontally (left/right or azimuth), using electronic motors controlled by the driver via a mirror position switch.
Usually, a single mirror position switch assembly is used, which includes a four-way rocker or joystick type switch for directing the two-directional movement of the mirrors as well as the left/right selector switch that switches between the two exterior side rearview mirrors so that they can be adjusted one at a time, independently of each other. The selector switch may also include a locked position so that movement of the joystick does not activate either of the mirror motors.
On vehicles provided with memory positioning, the mirrors can be automatically moved by suitable vehicle circuitry to a preset position established by the driver. Such circuitry can be implemented using position sensors on the mirrors to determine the instantaneous position of the mirrors in both the horizontal and vertical directions. These types of mirror positioning circuits are well known.
It is also well known to automatically adjust a rear vision system for a vehicle. For example, it is known to utilize adjustments by a vehicle operator to a driver side mirror to make automatic adjustments to a passenger side mirror without requiring the operator to make separate independent adjustment of the mirror. The automatic adjustment may be determined using a measured horizontal angle of the driver side mirror along with distance data related to a position of an inboard edge of each of the exterior side mirrors based on a popular setting method, such as a Blindzone setting method. It is also known to provide a synchronized rear vision system for a vehicle that allows a driver to use the Blindzone/Glare Elimination setting method. Such a system may include an automatic setting method detection and selection that allows a driver to use either the Blindzone or Glare Elimination setting method to adjust all mirrors of the rear vision system by adjusting the driver side mirror.
While the known systems are useful, there remains a need for a system and method that provides automatic, hands-free mirror adjustment in response to changes in the head position of the driver. There also remains a need for a system and method that provides enhanced safety by minimizing improper mirror positioning while maintaining the driver field of view. Therefore, it is desirable to provide a system and method for automatically adjusting vehicle mirrors based on the position of the head of the driver.